Prolapsing mucosal polyps: An underrecognized form of colonic polyp - A clinicopathological study of 15 cases

OBJECTIVE: Prolapsing intestinal mucosa occurs in many forms throughout the GI tract. We describe 15 patients with polypoid masses in the sigmoid colon and histological fea.tures of mucosal prolapse. METHODS: Fifteen patients with colon polyps demonstrating endoscopic and histological features of mucosal prolapse were retrospectively identified from our database. RESULTS: Twelve patients presented with signs and symptoms that were nonspecific, but consistent with mucosal prolapse, such as occult or gross intestinal bleeding and lower abdominal pain. Three patients were asymptomatic. The polyps occurred in the sigmoid colon, usually in association with diverticular disease, and appeared more often in men. Endoscopically, the polyps appeared to be well-circumscribed, hyperemic masses that contrasted sharply with normal-appearing adjacent mucosa. Histological features include glandular crypt abnormalities, fibromuscular obliteration of the lamina propria, and thickened and splayed muscularis mucosa. CONCLUSIONS: Prolapsing mucosal polyps of the colon are histologically similar to other mucosal prolapsing conditions in the GI tract, such as the solitary rectal ulcer syndrome, inflammatory cloacogenic polyps, inflammatory "cap" polyps, and gastric antral vascular ectasia, and should therefore be designated as part of the "mucosal prolapse syndrome." (Am J Gastroenterol 2002;97:370-376. (C) 2002 by Am. Coll. of Gastroenterology).